Ionomers of ethylene copolymers with alpha, beta-ethylenically unsaturated carboxylic acids are known in the art, wherein at least a portion of the carboxylic acid groups of the copolymer are neutralized to form carboxylate salts comprising alkali metal, alkaline earth metal or transition metal cations. See for example U.S. Pat. Nos. 3,264,272; 3,338,739; 3,355,319; 5,155,157; 5,244,969; 5,304,608; 5,542,677; 5,591,803; 5,688,869; 6,100,336; 6,245,858; 6,518,365; and U.S. Patent Application Publication 2009/0297747.
Aqueous dispersions of ionomers are also known in the art. See, for example; U.S. Pat. Nos. 3,896,065; 3,904,569; 4,136,069; 4,508,804; 5,409,765; and Japanese Patent Applications JP01009338 and JP05075769. They have been produced by dissolving the acid copolymer precursors in a solvent, neutralization of the acid functionalities with generally ammonia, amines or alkali metal ions, and dilution of the solution into water followed by partial or complete removal of the solvent. See for example U.S. Pat. Nos. 2,313,144; 3,296,172; 3,389,109; 3,562,196; 5,430,111; 5,591,806; British Patent GB1243303; Japanese Patent Applications JP50084687 and JP2009091426.
Aqueous ionomer dispersions have also been produced by heating acid copolymer precursors or ionomers in hot aqueous ammonia and other neutralizing agents. See for example U.S. Pat. Nos. 3,644,258; 3,674,896; 3,823,108; 3,872,039; 3,899,389; 3,970,626; 3,983,268; 4,400,440; 4,540,736; 5,160,484; 5,206,279; 5,330,788; 5,387,635; 5,550,177; 6,852,792; U.S. Patent Application Publication 2007/0117916; Japanese Patent Application JP06000872; and PCT Patent Application Publication WO2000/044801.
Aqueous ionomer dispersions have also been produced by dispersing the acid copolymer precursor in aqueous solutions of neutralizing agents at temperatures under high shear process conditions above the boiling point of water, necessitating the use of pressure vessels such as autoclaves and extruders. See for example U.S. Pat. Nos. 4,775,713; 4,970,258; 4,978,707; 5,082,697; 5,374,687; 5,445,893; 5,993,604; 6,482,886; 7,279,513; 7,528,080; 7,588,662; U.S. Patent Application Publications 2005/0100754; 2005/0271888; 2006/0124554; 2007/0137808; 2007/0137809; 2007/0137810; 2007/0137811; 2007/0137813; 2007/0141323; 2007/0144697; 2007/0243331; 2007/0284069; 2007/0292705; 2007/0295464; 2007/0295465; 2008/0000598; 2008/0000602; 2008/0041543; 2008/0073045; 2008/0073046; 2008/0118728; 2008/0135195; 2008/0176968; 2008/0182040; 2008/0216977; 2008/0230195; 2008/0292833; 2008/0295985; 2009/0194450; 2009/0253321; European Patent Application EP1163276; PCT Patent Application WO 2011/058119; WO 2011/058121; WO 2011/068525; and Japanese Patent Applications JP2958102; JP10006640; and JP50135141.
Aqueous ionomer dispersions have also been produced by dispersing the ionomer in aqueous solutions under high shear process conditions at temperatures above the boiling point of water, necessitating the use of pressure vessels such as autoclaves and extruders. See for example U.S. Pat. Nos. 4,173,669; 4,329,305; 4,410,655; 440,908; 6,458,897; Japanese Applications JP11158332; JP2000328046; JP2005075878; and PCT Patent Application Publication WO1999/10276.
Aqueous ionomer dispersions have also been produced by dispersing highly neutralized, high melt index (MI) ionomers in hot water. See for example U.S. Pat. Nos. 3,321,819; 3,472,825; and 4,181,566.